1. Field of the Invention
The present invention relates to a solid-state image pickup device having a built-in processing circuit such as an image sensor that processes an image signal, and it is used for, e.g., a mobile phone equipped with an image sensor, a digital camera, or a video camera.
2. Description of the Related Art
A reduction in size of a camera module for a mobile phone has been strongly demanded with a reduction in width of a mobile phone. Additionally, a camera module for a mobile phone, which is hardly destroyed even if it is dropped, has been demanded. Further, in recent years, an increase in the number of pixels, e.g., 5 mega pixels or more or 8 mega pixels or more has advanced to fulfill the demand for an improvement in image quality. In a multi-pixel sensor, a depth of field becomes shallow with a reduction in a pixel size. Therefore, an autofocus (AF) mechanism is required, and hence reducing a size of a module is difficult, and there is also problem that the module is prone to breakage when it is dropped. Each of Alon et al. (U.S. Pat. No. 7,065,256), Mendlovic et al. (U.S. Pat. No. 5,909,312), and Mendlovic et al. (U.S. Pat. No. 6,343,307) discloses a solid-state image pickup device that deepens a depth of field. However, a countermeasure for a problem of the chromatic aberration in a lens is not provided, a problem of occurrence of a false color in an image arises, or a resolution signal is not sufficiently obtained, and hence a color reproduced image having a sufficient resolution or a high quality is not acquired.